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Bioavailability and Granule Properties
Published in Dilip M. Parikh, Handbook of Pharmaceutical Granulation Technology, 2021
The Biopharmaceutics Classification System (BCS) is a drug development tool that allows estimation of the contribution of three fundamental factors including dissolution, solubility, and intestinal permeability, which govern the rate and extent of drug absorption from solid oral dosage forms [13]. Permeability is referred to as the ability of the drug molecule to permeate through a membrane into the systemic circulation.
Drug Nanocrystals
Published in Carla Vitorino, Andreia Jorge, Alberto Pais, Nanoparticles for Brain Drug Delivery, 2021
M. Ermelinda S. Eusébio, Ricardo A. E. Castro, Joäo Canotilho
The biopharmaceutics classification system (BCS) proposed by Amidon et al. [31, 32] categorises APIs according to some in vitro properties which have consequences for in vivo performance, namely aqueous solubility and membrane permeability. BCS class II drugs have limited oral bioavailability due to their low aqueous solubility, despite having high permeability. Low molecular weight, MW, lipophilic drugs, with MW up to 400–600 Da [33–35], should be able to cross the lipophilic BBB by passive diffusion. However, the necessary lipophilic characteristics result in low aqueous solubility, making many of these drugs BCS class II. The developability classification system (DCS) proposed by Butler and Dressman in 2010 [36, 37] further divides these APIs into those with dissolution-rate-limited oral bioavailability (i.e., DCS class IIa drugs) and those which are solubility-limited (i.e., DCS class IIb). For BCS class IV drugs, both low permeability and low solubility limit oral bioavailability.
Bioavailability of inhaled compounds
Published in Anthony J. Hickey, Heidi M. Mansour, Inhalation Aerosols, 2019
There have not been any bioequivalence studies based on clinical trials or in vitro data performed for inhalable products that have been published to this date. In fact, the in vitro measurements alone have been reported to lack predictive power (123), but there has been a research effort to develop a biopharmaceutics classification system (BCS) similar to that developed in the 1990s for oral dosage forms for immediate drug release. A group of scientists in the pharmaceutical inhalation field gathered to evaluate if such classification would be possible, and the results of these meeting were later reported (161). The authors concluded that, if such a classification system were developed, it may be useful for formulators and discovery chemists, but not suitable for regulatory purposes.
PEGylated Tween 80-functionalized chitosan-lipidic nano-vesicular hybrids for heightening nose-to-brain delivery and bioavailability of metoclopramide
Published in Drug Delivery, 2023
Saeed A. S. Al-Zuhairy, Mahmoud H. Teaima, Nabil A. Shoman, Mohamed Elasaly, Mohamed A. El-Nabarawi, Hossam S. El-Sawy
MTC has been classified as Biopharmaceutics Classification System (BCS) Class III; a high water-soluble drug with poor permeability, which explains the wide variability and poor bioavailability of orally administered MTC (Stosik et al., 2008). MTC also suffers from extensive hepatic metabolism, which significantly limits its efficiency (Lee & Kuo, 2010; Shakhatreh et al., 2019). However, MTC is one of the most renowned medications that widely prescribed for the treatment of nausea and vomiting. Regarding MTC site of action, the chemoreceptor trigger zone (CTZ) in the postrema region of the brain is where MTC mainly inhibits the dopamine D2 and serotonin 5-HT3 receptors, which are responsible for the antiemetic actions (Lee & Kuo, 2010). MTC is the sole FDA-approved antiemetic drug for the management of diabetic gastroparesis (Pasricha et al., 2006). The FDA clearly states that MTC is recommended for relieving symptoms in adults with acute and recurring diabetic gastroparesis and treating adults with gastroesophageal reflux symptoms (Shakhatreh et al., 2019). MTC also helps chemotherapy patients who are experiencing nausea and vomiting (Herrstedt et al., 2022).
Promising strategies for improving oral bioavailability of poor water-soluble drugs
Published in Expert Opinion on Drug Discovery, 2023
Bruna Rocha, Letícia Aparecida de Morais, Mateus Costa Viana, Guilherme Carneiro
Recent evidence has shown that roughly 75% of the substances for human use are poor water-soluble drugs (PWSDs), and around 40% of commercial products are based on PWSDs [3]. Various drug classification systems, such as the Biopharmaceutics Classification System (BCS) and Lipinski’s Rule of Five, have been utilized to streamline product development as attempts to predict the in vivo biological behavior from previous in vitro studies [4]. Considering the potential pharmacological activity of PWSDs, low aqueous solubility has remained one of the major obstacles in drug development. While problems related to the low permeability are generally corrected by adding absorption enhancers (e.g. fatty acids, bile salts, surfactants, and polysaccharides), the formulation development for PWSDs (BCS class II) is usually more complicated and potentially time-consuming given the numerous obstacles in preclinical and clinical trials due to inconsistent exposure to the drug. In addition, significantly higher drug amounts are required in the dosage form to compensate for poor solubility and pre-systemic metabolism, increasing development costs and prolonging the time to market [5].
Topical drug delivery to the retina: obstacles and routes to success
Published in Expert Opinion on Drug Delivery, 2022
Frequently, biologically active compounds fail to be developed into usable drugs due to their physiochemical properties. Then, the compounds are said not to possess drug-like properties. In the Biopharmaceutics Classification System (BCS) orally administered drugs are divided into four classes based on their aqueous solubility and ability to permeate biological membranes: class 1 – high solubility-high permeability drugs, class 2 – low solubility-high permeability drugs, class 3 – high solubility-low permeability drugs, and class 4 – low solubility-low permeability drugs [68]. The BCS is, for example, used by the pharmaceutical industry during drug discovery and development of oral drug formulations [69,70]. Also, the Biopharmaceutics Drug Disposition Classification System (BDDCS) teaches that there is a relationship between dug solubility/permeability and drug pharmacokinetics [71,72]. Both BCS and BDDCS show that there is a relationship between the physiochemical properties of a drug and its pharmacokinetic properties, including its bioavailability.